Possibility to extend formatters?

[erictheswift]

Words passed as parameters should be capitalized/lowercased depending on translation.

We're using message formats as the only source of translations.
It would be great to extend built-in formatters select, plural with own ones, like lowercased, capitalized.

I see this change would also involve intl-messageformat-parser package.
Do you think it's a good idea?

[caridy]

@metallium we are implementing the specified formatters from ICU Messages: http://userguide.icu-project.org/formatparse/messages.

I believe lowercase, and capitalization should be baked into the translation rather than a runtime cost. It might require some duplications in the messages you send to the client side, but I think it is worthy to keep that separation.

[erictheswift]

These injected words are dynamic and are used in lots of messages. Thought about that, but it seems more natural to polish it in concrete translation.

[erictheswift]

formatter customization is available by default in c# implementation
https://github.com/jeffijoe/messageformat.net/blob/master/src/Jeffijoe.MessageFormat/Formatting/FormatterLibrary.cs#L25

[erictheswift]

@caridy you can still implement the specified formatters from ICU Messages, but make the set of formatters customizable.

[caridy]

ah, thanks for the link @metallium. I will talk to the other folks about this, give us some time to review it. /cc @ericf

[ericf]

@metallium can you write an example message in the message syntax to demonstrate what you're suggesting? I think it would help be better understand what you're running into and how you're proposing to solve it.

[erictheswift]

example that is unsolveable now:

format('Add 1 {itemName}', {itemName: 'Bug'}) => 'Add 1 Bug'

data remains the same for all languages, but specific language can force lowercasing of words inside string (I still keep using English here)

format('Add 1 {itemName, lowercased}', {itemName: 'Bug'}) => 'Add 1 bug'

as for me, formatters seem to be good extensibility point, allowing to define

• text/numbers transformation aliases
• specific stuff like html wrappers around text parts (allowing to add specific behavior on message parts while preserving source string sanity)
• ...

[ericf]

@metallium I see, so you want to define lowercased() in your app code, pass it to IntlMessageFormat() as a custom format, and when used in a message it'll be called the locale and value?

[erictheswift]

yep, to make it possible to provide custom formatters, e.g.

new IntlMessageFormat('The price is: {price, number, USD}', 'en-US', {
    lowercased: function(value) {
        return value.toLowerCase();
    }
})

in general it would be great if default formatters (plural, select, selectordinal, ...) would use the same API as custom ones

[rlivsey]

Another potential use-case for this I've had in the past (#99) is to turn lists into sentences, it would be great to be able to define a sentence formatter:

format('Selected {items, sentence}', {items: ['one', 'two', 'three'}) 
// => "Selected one, two and three"

[caridy]

@rlivsey that's a different feature request, and it is an ongoing effort: tc39/ecma402#33

[rlivsey]

@caridy awesome, thanks for pointing me towards that, I've added a comment to the original issue pointing others over there too.

[nadavivry]

Pretty sure it's the same feature request - in my case, I have a requirement for adding a new "style" option for the number formatter.

I need to insert the following function as a custom style:

function (val) {
  var v = "";

  var negative = false;
  if (val < 0) {
    negative = true;
    val = Math.abs(val);
  }

  if (val >= 1e12) {
    v = String(Math.round(val / 1e11) / 10) + "T";
  } else if (val >= 1e9) {
    v = String(Math.round(val / 1e8) / 10) + "G";
  } else if (val >= 1e6) {
    v = String(Math.round(val / 1e5) / 10) + "M";
  } else if (val >= 1e3) {
    v = String(Math.round(val / 1e2) / 10) + "K";
  } else {
    v = String(Math.round(val * 10) / 10);
  }

  if (v == "undefined") {
    v = "";
  } else {
    if (negative) {
      v = "-" + v;
    }
  }

  return v;
}

[longlho]

This use case should be handled by our skeleton support + numberformat es2020 polyfill

[anosov-otg]

@longlho how can I specify currency dynamically using skeleton formatting?

No problem (from documentation):

The price of this bagel is {num, number, ::sign-always compact-short currency/GBP}

Problem: I don't know the currency at this point, it must be dynamic. This format doesn't work:

The price of this bagel is {num, number, ::sign-always compact-short currency/{currency}}

[longlho]

You cannot. You'll have to format it as a passed in values